This invention relates to an endoscope air sending device for sending air into a body cavity such as the stomach, and more particularly to the arrangement of components including valves and a compressor which are provided for sending air into the body cavity.
An endoscope air sending device is known in the art which is so designed that the air whose pressure is increased by an air compressor is discharged by controlling a valve, and the air thus discharged is sent into the body cavity through a tube. In the device, during discharging, the compressor is operated while a pressure control valve controls the pressure of the air to be discharged. The pressure control valve adjusts the sectional area of the air flowing path, to thereby control the pressure of the air.
The pressure control valve is only able to decrease the pressure of the air to be discharged. Therefore, it is necessary to provide a large compressor of high output type which can send a high pressure air. However, as the compressor is of the higher output type, it generates more noise. Hence, during the medical operation, the compressor operating at all times is noisy. Furthermore, because of the structure of the pressure control valve, the endoscope air sending device cannot discharge the air with fine pressure adjustment. The endoscope air sending device cannot accurately perform the air pressure control over a wide range of from low pressure to high pressure.